How to optimized Multiple CASE statement

Hi..

Somebody please help me out to use most optimized Multiple CASE statement in below example.. 

Select
CAST(COUNT(DISTINCT(CASE WHEN period_id <350 THEN period_id END)) AS DECIMAL(30,0))  AS Column1,                  CAST(COUNT(DISTINCT(CASE WHEN period_id >=351 AND period_id<=375 THEN period_id END)) AS DECIMAL(30,0)) AS Column2,                                
CAST(COUNT(DISTINCT(CASE WHEN period_id >=376 AND period_id<=400 THEN period_id END)) AS DECIMAL(30,0)) AS Column3,                             
CAST(COUNT(DISTINCT(CASE WHEN period_id >=401 AND period_id<=450 THEN period_id END)) AS DECIMAL(30,0)) AS Column4,                             
CAST(COUNT(DISTINCT(CASE WHEN period_id >=451 AND period_id<=575 THEN period_id END)) AS DECIMAL(30,0)) AS Column5,
CAST(COUNT(DISTINCT(CASE WHEN pmc ='UVS' THEN pmc END)) AS DECIMAL(30,0)) AS Column6,                                
CAST(COUNT(DISTINCT(CASE WHEN pmc ='VAL' THEN pmc END)) AS DECIMAL(30,0)) AS Column7                            
FROM [Table1]

Thanks in Advance,

Deepak Goyal